Available online at www.pelagiaresearchlibrary.com Pelagia Research Library Advances in Applied Science Research, 2011, 2 (5):561-571 ISSN: 0976-8610 CODEN (USA): AASRFC 561 Pelagia Research Library Survey of heavy metal contaminations of cassava mash and maize corns dried along the highways in some selected states in northern part of Nigeria Kolawole Sunday Adebayo 1 and Odoh Rapheal 2 1 Department of Chemistry, Faculty of Science, University of Abuja, Abuja, Nigeria 2 Department of Chemistry, Faculty of Science, Ahmadu Bello University, Zaria, Kaduna state, Nigeria ______________________________________________________________________________ ABSTRACT Heavy metal concentrations were determined in some of the crops (cassava mash and maize grains) dried along highways “express” in selected states (Benue, Nasarawa and Taraba) in Northern part of the country (Nigeria). The results of chemical analysis indicated that the heavy metal contents of the food crops (cassava mash and maize grains) dried along the highways were higher than the heavy metal contents of food crops (cassava mash and maize grains) from the control areas. The overall ss ranged from 0.210-0.410g/g, 11.120-18.120 g/g, 10.200-17.010 g/g, 0.680-0.920 g/g 0.350-0.660 g/g and 9.520-21.330 g/g for Cd, Cu, Mn, Ni, Pb and Zn in the cassava mash samples, while in the maize grains the heavy metal concentrations ranged from 0.180-0.350 g/g, 5.780-9.880 g/g, 7.850-12.250 g/g, 0.521-0.880 g/g, 0.310-0.450 g/g and10.990-16.550 g/g for Cd, Cu, Mn, Ni, Pb and Zn respectively. Cd concentrations were above WHO/FAO (2007) and Commission regulation (EU 2006) safe limits and Pb above Commission regulation (EU 2006) but below the WHO/FAO (2007) safe limits. Regular monitoring of heavy metals in the food crops dried along the highways is also necessary. Keywords: heavy metal, contamination, maize and cassava. ______________________________________________________________________________ INTRODUCTION For many decades public health authorities have considered mineral contamination of foods and water as a matter of concern [1]. Although some metals are essential for life, all metals are toxic at sufficiently high concentrations; for there is a narrow window between what is essential and what is toxic [2]. Because many biological systems exist naturally on the margin of metal toxicity, the physical and geochemical redistribution of toxic metals in environments by human activities has a strong potential to disrupt ecosystem [3].